2026 Principia Gravel 20 Base 61cm
Build
700C/29 in × 45 mm
Insights
Average stack and reach vs trend of all-road/gravel bikes
Design deviates from other sizes of Principia Gravel 20
Stack and Reach vs. Category Trend
View all sizes
Geometry
| Stack | 663.9mm |
| Reach | 410.9mm |
| Stack to Reach Ratio | 1.62:1 |
| Seat Tube Length, C-T | 610mm |
| Top Tube Length, Effective/Horizontal Center | 595mm |
| Top Tube Slope | 7.6deg |
| Head Tube Angle | 73deg |
| Seat Tube Angle | 74.5deg |
| Head Tube Length | 215mm |
| Bottom Bracket Drop | 67mm |
| Bottom Bracket Height | 289mm |
| Chainstay Length | 435mm |
| Chainstay Length Horizontal | 429.8mm |
| Front-Center | 644.3mm |
| Front-Center Horizontal | 641.4mm |
| Wheelbase | 1071.2mm |
| Fork Offset/Rake | 45mm |
| Fork Length, Unknown | 425mm |
| Trail | 61.8mm mid/neutral |
| Mechanical Trail | 59.1mm |
| Wheel Flop | 17.3mm |
| Tire to Pedal Spindle Distance With 170 mm cranks | 118.3mm |
| Pedal Spindle to Ground Clearance With 170 mm cranks | 119mm |
Base Build
| Wheel Size | 700C, 29 inch (622mm BSD) |
| Tire Width | 45mm |
| Tire Outer Diameter | 712mm |
| Bike Length with Tires | 1783.2mm |
| Crank Length | 170mm |
| Handlebar Width | 440mm |
| Stem Length | 100mm |
| Stem Angle | -7deg |
| Suspension Type | Rigid, non-suspension corrected |
| Bar Type | Drop Bar |
| Frame Material | Aluminum |
| Fork Material | Aluminum |
| Brake Type | Disc |
Source:https://principiabikes.com/gravel/gravel-aluminium/gravel-20---grey-pg-2591